I'm upgrading a .NET 2.0 WinForms application to .NET 4.5.2 and am receiving two warning on this block of code:
Public Sub ShowFormAsMdiChild(ByVal newFormType As Type, _
ByVal mdiParentType As Type, _
Optional ByVal SearchID As String = "",
Optional ByVal curType As SearchType = SearchType.Residential)
If SearchID = "" Then
Dim F As Form
F = CType(Activator.CreateInstance(newFormType), Form)
F.MdiParent = CType(Activator.CreateInstance(mdiParentType), Form).ActiveForm
F.Show()
Else
Dim F As Form
Dim args(1) As Object
args(0) = SearchID
args(1) = curType
F = CType(Activator.CreateInstance(newFormType, args), Form)
F.MdiParent = CType(Activator.CreateInstance(mdiParentType), Form).ActiveForm
F.Show()
End If
End Sub
I receive the following warning on the two lines that set F.MdiParent:
Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.
The problem is that the ActiveForm Property is a shared Property and because the code is creating a new instance of the Form, calling the a Form's shared Property causes the warning.
Is there a better way to implement without the warning? Preferred answer in VB.NET, but I can translate if you only know how in C#.
There's no need to create a new instance of the MDI parent type, and then cast it to Form
. ActiveForm
is a shared property of the Form
class, so you should access it through the class name, not through an instance.
F.MdiParent = Form.ActiveForm
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